1. Field of the Invention
The present invention relates to a test apparatus for use in a burn-in test, for example, and more particularly to a test apparatus and method capable of reducing contact pressure with respect to a test object (e.g., an IC package) and allowing easy replacement of only a coupling member of the apparatus.
2. Description of the Related Art
A multitude of IC packages are manufactured from a wafer and are individually separated. Thereafter, the individual IC packages are subjected to the burn-in test. The burn-in test is performed to determine whether or not each IC package is free of a cut in wiring or the like even under a predetermined high-temperature accelerating condition and thus is qualified for a final operation test.
Conventionally, as illustrated in FIG. 26, the burn-in test is performed by placing the individual IC packages 3 in a multitude of IC sockets 2 formed in a burn-in board 1. For example, as illustrated in FIG. 27, each IC socket 2 includes a recess 4 for accommodating the individual IC package 3, and covers 5 for applying biasing force toward the inside of the recess 4 to press the IC package 3 set in the recess 4 into the recess 4. As illustrated in FIG. 27, a bottom surface of the recess 4 is provided with a multitude of contact pins 6 which contact connecting terminals 3a, such as BGAs, of the IC package 3 to be in conductive contact with and connected thereto.
Examples of conventional IC sockets are described in Japanese Unexamined Patent Application Publication No. 9-232057 and Japanese Unexamined Patent Application Publication No. 2002-357622, for example.
As described above, the IC socket 2 is formed for the individual IC package 3 on the conventional burn-in board 1. Due to a structural restriction that the IC socket 2 accommodates and presses the IC package 3 thereinto, there is a limit in downsizing the IC socket 2. Thus, it is difficult to increase the number of the IC sockets 2 formed on the burn-in board 1 of a predetermined size. Therefore, to perform the burn-in test at one time on the IC packages 3 of a larger number than previously, structures of a conventional test apparatus and the conventional burn-in board need to be improved.
Further, each of the contact pins 6 provided in the IC socket 2 applies high contact pressure to the corresponding connecting terminal 3a of the IC package 3. Therefore, to securely hold the IC package 3 within the IC socket 2, a pressing mechanism (e.g., the covers 5 shown in FIG. 27) tends to have a complex structure. Furthermore, it is difficult to evenly apply the contact pressure to all of the contacting terminals 3a. Also, the high contact pressure damages the contacting terminals 3a in some cases.
In addition, when one of the contact pins 6 fails to operate properly, replacement of only the failed contact pin 6 is not allowed. That is, the entire burn-in board 1 including the failed contact pin 6 needs to be replaced. As a result, maintenance fee is increased.